Carburetor for internal-combustion engines



Oct. 28, 1930. .A. DROGO CARBURETOR FOR INTERNAL COMBUSTION ENGINESFiled Feb. 20. 1922 Fig.8.

115s Fig.1.

I 1. Fun 5 5 2 a 4 5 2 uJ 2 1 R m .9 8 w 5 I 7 fi 7 1 2, 6 J 1 e rnvvcwme Ava-MEN 019060 ZTTORNEYS Patented Oct. 28, 1930 PATENT OFFICAUBELIEN DROGO, OF PARIS, FRANCE GABB'UBETOR FOR INTERNAL-COMBUSTIONENGINES Application filed February 20, 1922, Serial No. 538,033, and inFrance February 28, 1921.

The object of the invention is to provide a carburetor free of thecapillary phenomena connected with the usual atomizing nozzle andcapable of supplying proper explosive mixtures with both heavy and lightdistillates.

This invention will be best understood from a consideration of thefollowing detailed description, reference being had tmthe accompanyingdrawing.

Inthe drawings:

Figure 1 is a lon 'tudinal vertical section of the carburetor ta onalong the line 1-1 of Figure 3.

Figure 2 is a fragmentary vertical section taken along the line 2-2 ofFigure 3.

Figure 3 is a horizontal sectiontaken along the line 33 of Figure 1.

Figure 4 is a fragmentary vertical section taken along the line 4-4 ofFigure 3.

Figure 5 is a fragmentary horizontal section taken along the line 55 ofFigure 4.

Fig. 6 is a diagrammatic view of the entire carburetor particularlyillustratin the relative arrangement and location of t e variouspassages and connections.

Referring more particularly to the drawings, 1 designates a floatchamber of the carburetor which includes a float 2 of any ap- 3 provedconstruction. The float chamber has a cover 2" at its upper end in whichis formed the upper end 3 of a passage which is in communication with aPitot tube 4, the free end of said tube opening at the mouth of the airintake 6 of the carburetor, with the end 5 being located in thedirection of the flow of the air to said motor.

The float chamber 1 is connected by a passa e Z with a suction well 8which is provided with a plug 9 having a properly diminished aperture10. O enmg above the plug is an end 11 of a fuel intake conduit 12projecting into a distributor pipe 13 which is connected either directlyor through convenient tubes with the inlet passage 14 of the motor. Theinlet passage 14 is in communication with air intake 6, the suctionbeing regulated in the said intake by a throttle valve 16 which iscontrolled throu h a cam member 20 59 actuated by a shaft 21. 'I heshaft is operated in any approved manner through connections 1with theusual throttle control of an automo- In the opening of the intake 6 isarranged the endof a tube 17 which I describe as an up-stream Pitottube, the said end being directed in an inverse position to the end 5 ofthe Pitot tube 4 and the said tube 17 through a passage 17 a and apassage 24 in the cover 2 connects the opening ofthe intake 6 with theupper part of the well 8 which is provided for feeding the liquid fuel.

The foregoing assembly is diagrammatically illustrated in Figure 6 andfunctions in the following Way:-When the motor is at rest, the end ofsuction tube 12 is slightly submerged in the fuel contained in suctionwell I take tube 6. The pressure in the float chamber and in the suctionwell will, therefore, be nearly equal, and fuel will flowfrom floatchamber to suction Well by the action of gravity. The diameter of theaperture in plug 11, and the level of' liquid in the float of fuelintake conduit 12 is neither completelysubmerged in, nor entirely abovethe level suction well 18 and, since aperture 10 in plug 11 limits therate of flow by gravity of fuel from the float chamber to the suctionwell, it becomes 'necessary to provide supplemental means foraccelerating the rate of plished by the upstream and downstream Pitottubes 4 and 17 The increased velocity of the air flowing into air intakeconduit 6 reacting on the oppositely directed Pitot tubes, creates apressure differential in float owof fuel through aperturelO 1nproportion to the increasing speed of the motor. This is accomchamberare adjusted so that the extremity the nozzle of an ordinary carburetor.

chamber 1 and suction well 8 which has the effect of forcing fuel intothe suction well at a rate which is a function of the velocity of theair passing through said air intake tube. ThePitot-tubesfunction,therefore,to maintain the liquid in suction well 8at the same level as at idling speed i. e. so that the end of suctiontube 12 is neither submerged in, nor above the level of, the liquid inthe suction well. From the foregoing, it is evident that the suctiontube will aspirate an emulsion of fuel and air through extremity 11throughout the range of motor speeds. The suction tube thus replaces,and is in a rough'way equivalent to, It will be noted however, that nocapillary phenomena are involved in its operation as is the case withthe usual suction nozzle, and as a consequence, none of the usualdifficulties at starting and idling speeds are encountered.

Should, for any reason, the level of the float chamber 1 be maintainedconstant the liquid will flow through the plug 10 with a speed which isproportional to the speed of the air in the suction pipe 6 at the planepassing across the orifice of said pipe. It is possible, when the motoris running slowly, to have the proportion increased by taking the fuelfrom the level 7Y lower than the level 7 Y thus having a supplementalcharge equal to the depression due to the suction of air at the orificeof the pipe 6. This effect is a trifle at high speeds but it is verynoticeable at low speeds as well as when starting the motor. In thismanner the starting of the motor is made easier.

The Pitot tube 4 is connected through a passage 22 with passage 3 whichis formed in the cover 2 A short passage 23 extends downwardly from thepassage 3 and opens into the top of the well or float chamber 1 andabove the level of the liquid. A valve 26 in the passage 27 which opensinto the intake 6 adjacent the valve 16 forms a by-pass from the passage22 to the intake 6.

The distributor 13 has a perforated end or rose 13 which is adapted tobe disposed within the valve chamber of the internal combustion enginefor further breaking up the fuel and air before it enters the engine. Itwill be appreciated that while I have shown one tube 13 any number maybe employed which may be required for the purpose.

It may happen that owing to the special arrangement of the motor it maybe possible to directly bring to the valve chamber the emulsion ofliquid fuel and air. In this instance the suction pipe 12 will opendirectly into the pipe 6 at a convenient point between the throttle 16and the motor. In this construction the valve 26 will be opened forplacing the passage 3 directly in communication with the intake 6 at apoint adjacent the valve 16 and through the passage 27.

What I claim is:

1. A carburetor comprising in combination an air intake conduit, a valvecontrolling said conduit, 2. well having an opening in the wall thereofcommunicating with the atmosphere, a fuel conveying system including apassageway having one extremity communicating with said well and theother extremity communicating with said air intake conduit, saidpassageway being separate from, and independent of, said opening in thewall of the well, a fuel reservoir communicating with said well throughan orifice of predetermined dimensions and means operable to vary theflow of fuel through said orifice in accordance with variations of thevelocity of the air flowing into the air intake conduit.

2. A carburetor comprising in combination an air intake conduit, a valvecontrolling said conduit, a suction well having an opening in the wallthereof communicating with the atmosphere, a suction conduit having oneextremity terminating inside the suction well and another extremity incommunication with the air intake conduit, said suction conduit beingseparate from, and inde endent of, the opening in the wall ofthe suctionwell, an enclosed fuel supply chamber communicating with said suctionwell, and means including a Pitot tube for varying the pressure in saidfuel supply chamber in accordance with variations of the velocity of theair flowing into the air intake conduit.v

3. A carburetor comprising in combination an air intake conduit, a valvecontrolling said conduit, an enclosed suction Well, a suction conduithaving one extremity terminating inside the suction well and havinganother extremity in communication with the air intake conduit, a fuelsupply chamber communicating with said suction well, and means includinga Pitot tube for varying the pressure in the upper part of the suctionwell in accordance with variations of the velocity of the air flowinginto the air intake conduit.

4. A carburetor comprising in combination an air intake conduit, a valvecontrolling said conduit, a suction well, a constant level chambercommunicating with said suction well through an orifice of predetermineddimensions. a suction conduit having one extremity in communication withthe air intake conduit and having another extremity terminating insidethe suction well, an upstream Pitot tube positioned in the air intakeconduit and extending to the upper part of the constant levelchamber,'and a downstream Pitot tube positioned in the air intakeconduit and extending to the upper part of the suction well.

5. A carburetor comprising in combination an air intake conduit, a valvecontrolling said conduit, a well having an opening in the wall thereofcommunicating with the atmosphere, a suction conduit having oneextremity terminating inside the Well and having another extremitycommunicating with the air intake conduit at a point situateddownstreamward with relation to said valve, said suction conduit beingindependent of the opening in the wall of said well, and a fuelreservoir communicating with said well through an orifice ofpredetermined dimensions.

6. A carburetor as defined in claim 5 in combination with meansincluding a Pitot tube for varying the rate of flow of fuel through saidorifice in accordance with variations of the velocity of the air flowinginto the air intake conduit.

In testimony I have hereunto set my hand at Paris, France, this 3d dayof'February, 1922.

AURELIEN DROGO.

